Process of making pistons



J. FLAMMANG.

PROCESS OF MAKING PISTONS.

APPLICATION FILED nun 2s. 191a.

' 1,336,689, 7 Patented Apr. 13, 1920.

UNITED; STATES OFFICE.

JOHN FLAMMANG, or sr. Louis, mrssoum," ASSIGN'OR To OTTMAR e. sunk, or s'r.

r LOUIS, mssounr.

rnoonss or MAKING- rrsrons.

Specification of Letters Patent. Patented Apr. 13, 1920- Application filed llay 23, 1918. Serial No. 236,188.

To all whom it may concern:

Be it known that I, JOHN FLAMMANG, a

' citizen of the United States, residing at St. Louis, Missouri, have invented a new and useful Process'of Making Pistons, of

which the following is a specification.

This invention relates to the art of manufacturing pistons.

An object of the invention is to provide a novel process or method of procedure for use in the construction of pistons to be used in engines, motors, pumps and the like, whereby the resiliency of the metal of which the piston is composed may be utilized to press an expansible portion of the piston against the wall of the cylinder in which it is to operate and form a close joint there; with, thus-dispensing with the necessity of using piston rings and pacln'ngi, 4

Another object of the invention is to provide a novel process or method of procedure forv manufacturing a piston of a hollow body and an integral top or head which expands by the resiliency of the metal to form close contact with the cylinder wall and thereby dispenses with the necessity of using piston rings or packing.

Other objects will appear from the -following description in which reference is made to the accompanying drawing illustrating a piston in different stages of its manufacture, and in which- Figure 1 is an elevation partly in section of a casting from which the piston may be made. I

Fig. 2 is \an elevation. partly in section of a casting after a portion thereof has been divided into segmental sections and after the casting has been otherwise treated.

Fig. 3 is a similar view of the piston cast-.

ing in another. stage of the development of' the piston.

' Fig. 4 is an elevation of the casting after the supports or connections for the segmental sections of the upper portion thereof have been placed under tension preparatory for the piston to be finished.

' Fig. 5 is an elevation of the finished piston.- Fig. 6 is a view of the piston mounted within a cylinder for which it is intended, parts of the piston being broken away.

Fig.- 7 is a view illustrating one of the details of the piston.

' In its initial form the casting from which the piston is made is hollow and consists of the lower ring 1, an upper ring 2, connections 3 integrally uniting the lower and upper rings, bosses 4 integral with the connections 3 throughowhich the holes for the wrist pin are to be formed, a top or head plate 5 integral with the ring 2 and projections 6 extending upwardly from the top plate.

The upper ring -1 and the top plate of the casting are then cut or divided as indicated at 7 (Fig. 2) to divide the upper ring and the top plate into segmental sections which are integrally united with the lower ring 1 by the connections 3. In the form shown the cut 7 extends transversely of the axis holes, the placing of the wrist pin forces apart or bends the connections 3, thus separating the segmental sections of the upper portion of the ring. The wrist pin is secured in its mounting by set screws 10.

Next the groove or ehannel 11 is formed in the. head or top plate of the casting, a part of the groove being at each side of the i cut 7 The walls of the groove are formed obliquely, being inclined toward each other so that the upper portion of the entrance to the groove is narrower than its base. A key or plate 12 having inclined side edges to match the side walls of the groove 11 is placed in said groove so that when the piston is compressed, as shown in Figs. 4 and 6, the key or plate will be held in the groove. Also keys 13 are seated in grooves in the piston below the ends of the key'12. I

' Eitherbefore or after the keys 12 and 13 are placed-in the grooves provided therefor the piston is ground'or turned and finished as-to its outer surface, the lower portion of the piston being formed of a diameter slightly less than the diameter of the cylinder for which it is intended, as shown by dotted lines 14. The top plate and upper ring 2 are finished to a size the diameter of whichis equal to the diameter of the cylinder 'is provided with a number of circumferential oil grooves 18 in the lower ring 1 and, after being finished, the nut 17 is. turned'to relieve the tension on the connections 3,.

i thereby permitting the upper ring to open as shown. Also, at some stage in its manufacture the upper edge of the ring 1 is beveled to provide a scraper 19 for the oil, and 'the lower edge of the ring 2 is also beveled to provide a scraper 20 for "the oil. The scrapers 19 and 20 scrape the oil from the surface of the cylinder during upward and downward movement of the piston therein.

When mounted in a cylinder the wall of the cylinderfprevents displacement of the vkeys 13 which are in the form of narrow plates mounted in grooves crossing the cuts 7 below the key 12, thus sealing or closing the cut 7 and preventing the pass'a e of gas, steam or other operating agent. hen the pistonis under compression a key 12 forms relatively close contact with the side walls of the groove in which it is mounted, but it will be understood that said key 12 is slightly narrower than the groove in which it is seated when the piston is mounted in the cylinder, so that there may be proper provision for the compression of the piston when it becomes heated in the course of operation,

The nut 17 may be prevented from turning by the employment of a holding device,

one form of which is illustrated in Fig. 7,-

and which'consists of a spring 21 mounted in a notch or seat in the head of the piston and enga ing one of the side walls.

The or er ofprocedure as to the formation of the piston may be varied in many respects without departure from the scope of the invention. as claims.

What I claim and desireto secure by Let-. ters Patent,- is

1. The process of making a piston, which consists in forming a hollow piston body with a lower ring, an upper ring and atop.-

plate which are integrally united; splitting the upper ring and thetop plate to form segmental sections; and finishing the piston to a size in which the upper ring is of the same diameter as the diameter of the cylinder for which the piston is intended and the remaining portion of the piston is of smaller diam- ,set forth in theappended 2. The process of making a piston, which consists in forming a hollow piston body composed of a lower ring, an upper ring, and a top plate which are integrally united; dividing the upper ring and the top plate into segmental-sections integrally connected mental sections of the upper ring while cornpressed are of a size equal to the size of the diameter of the cylinder for which the piston is intended, and which when released from the tension will expand to a size in excess of the diameter of the cylinder for which the piston is intended.

3. The process of forming a piston, which consists in forming a hollow piston body composed of a lower ring, an upper ring, and a top plate which are integrally united; dividingthe upper ring and the top plate into segmental sections integrally connected with the lower ring; compressing said sections toward each other to place the material.

under tension; finishing the piston while under tension to a size in which the segmental sections of the upper ring while compressed are of a size equal to the size of the diameter ofthe cylinder for which the piston is intended, and which when released from the tension will expand to asize in excess of the diameter of the cylinder for 100 which the piston is intended; and finishing the remaining portion of the piston to a size'less than the diameter of. the cylinder for which the piston is intended.

4. The process of making a piston, which 105 consists in forming a hollow piston body with a'lower ring, an upper ring, and a top plate which are integrally united; splitting the top plate and the upper ring-into segmental sections; placing the material of the 110 piston body under tension by drawing the sections of the upper ring and the top plate toward each other; finishing the upper ring and top plate while the material is under 7 tension to a size equal to the diameter of the 115 cylinder for-which the piston is intended; and closing the spaces between the segmental'sections.

" 5. The process of making a piston, which consists in forming a hollow piston body 120 composed of a lower ring, an upper ring, and a top plate which are-integrally united; splitting the upper ring and the top plate into segmental sections; placing the material under tension by drawing the segmental 5 sections of the upper ring and top plate toward each other; finishing the upper ring andtop plate while the material is under tension to a size equal to the diameter of the cylinder for which the piston is in- 13 0 eter than the diameter-of the cylinder for which the piston is intended.

tended; removing the tension from the material to permit the segmental sections to expand; and closing the spaces between the segmental sections of the top' plate.

6. The process of making a piston, which consists of forming a piston body composed of a lower ring, an upper ring, and a top plate which are integrally united; splitting the upper ring and the top plate into segmental sections; drawing the segmental sections of the top plate and the upper ring toward each other to place the material under tension; finishing the top plate and upper ring to a diameter equal to the diameter of the cylinder for which the piston is intended while the material is under tension; finishing the lower portion of the piston body to a size less than the diameter of the cylinder for which the piston is intended; removing the tension to permit the segmental sections of the top plate to expand so that when the piston is placed in a cylinder the periphery of the upper ring will be pressed against the cylinder wall by the resiliency of the material.

7. The process of making a piston which consists of forming a piston body composed of a lower ring, an upper ring, and a top plate which are integrally united; splitting the upper ring and the top plate into segmental sections; drawing the segmental sections of the top plate and the upper ring toward each other to place the material under tension; finishing the top plate and upper ring to a diameter equal to the diameter of the cylinder for which the piston is intended While the material is under tension; finishing the lower portion of the piston body to a size less than the diameter of the cylinder for which the piston is intended; removing thetension to permit the segmental sections of the top plate to expand so that when the piston is placed in a cylinder the periphery of the upper ring will be pressed against the cylinder wall by the resiliency of the material; and closing the spaces between the segmental sections of the top plate.

JOHN FLAMMANG. 

